rhg: fix `clippy` warnings

Differential Revision: https://phab.mercurial-scm.org/D8955

rust/rhg/src/error.rs

@@ -1,110 +1,110 b''
 use crate::exitcode;
 use crate::ui::UiError;
 use hg::operations::{FindRootError, FindRootErrorKind};
 use hg::utils::files::get_bytes_from_path;
 use std::convert::From;
 use std::path::PathBuf;
 
 /// The kind of command error
 #[derive(Debug)]
 pub enum CommandErrorKind {
     /// The root of the repository cannot be found
     RootNotFound(PathBuf),
     /// The current directory cannot be found
     CurrentDirNotFound(std::io::Error),
     /// The standard output stream cannot be written to
     StdoutError,
     /// The standard error stream cannot be written to
     StderrError,
     /// The command aborted
     Abort(Option<Vec<u8>>),
 }
 
 impl CommandErrorKind {
     pub fn get_exit_code(&self) -> exitcode::ExitCode {
         match self {
             CommandErrorKind::RootNotFound(_) => exitcode::ABORT,
             CommandErrorKind::CurrentDirNotFound(_) => exitcode::ABORT,
             CommandErrorKind::StdoutError => exitcode::ABORT,
             CommandErrorKind::StderrError => exitcode::ABORT,
             CommandErrorKind::Abort(_) => exitcode::ABORT,
         }
     }
 
     /// Return the message corresponding to the error kind if any
     pub fn get_error_message_bytes(&self) -> Option<Vec<u8>> {
         match self {
             // TODO use formating macro
             CommandErrorKind::RootNotFound(path) => {
                 let bytes = get_bytes_from_path(path);
                 Some(
                     [
                         b"abort: no repository found in '",
                         bytes.as_slice(),
                         b"' (.hg not found)!\n",
                     ]
                     .concat(),
                 )
             }
             // TODO use formating macro
             CommandErrorKind::CurrentDirNotFound(e) => Some(
                 [
                     b"abort: error getting current working directory: ",
                     e.to_string().as_bytes(),
                     b"\n",
                 ]
                 .concat(),
             ),
             CommandErrorKind::Abort(message) => message.to_owned(),
             _ => None,
         }
     }
 }
 
 /// The error type for the Command trait
 #[derive(Debug)]
 pub struct CommandError {
     pub kind: CommandErrorKind,
 }
 
 impl CommandError {
     /// Exist the process with the corresponding exit code.
-    pub fn exit(&self) -> () {
+    pub fn exit(&self) {
         std::process::exit(self.kind.get_exit_code())
     }
 
     /// Return the message corresponding to the command error if any
     pub fn get_error_message_bytes(&self) -> Option<Vec<u8>> {
         self.kind.get_error_message_bytes()
     }
 }
 
 impl From<CommandErrorKind> for CommandError {
     fn from(kind: CommandErrorKind) -> Self {
         CommandError { kind }
     }
 }
 
 impl From<UiError> for CommandError {
     fn from(error: UiError) -> Self {
         CommandError {
             kind: match error {
                 UiError::StdoutError(_) => CommandErrorKind::StdoutError,
                 UiError::StderrError(_) => CommandErrorKind::StderrError,
             },
         }
     }
 }
 
 impl From<FindRootError> for CommandError {
     fn from(err: FindRootError) -> Self {
         match err.kind {
             FindRootErrorKind::RootNotFound(path) => CommandError {
                 kind: CommandErrorKind::RootNotFound(path),
             },
             FindRootErrorKind::GetCurrentDirError(e) => CommandError {
                 kind: CommandErrorKind::CurrentDirNotFound(e),
             },
         }
     }
 }

rust/rhg/src/ui.rs

@@ -1,106 +1,100 b''
 use std::io;
 use std::io::{ErrorKind, Write};
 
 #[derive(Debug)]
 pub struct Ui {
     stdout: std::io::Stdout,
     stderr: std::io::Stderr,
 }
 
 /// The kind of user interface error
 pub enum UiError {
     /// The standard output stream cannot be written to
     StdoutError(io::Error),
     /// The standard error stream cannot be written to
     StderrError(io::Error),
 }
 
 /// The commandline user interface
 impl Ui {
     pub fn new() -> Self {
         Ui {
             stdout: std::io::stdout(),
             stderr: std::io::stderr(),
         }
     }
 
     /// Returns a buffered handle on stdout for faster batch printing
     /// operations.
     pub fn stdout_buffer(&self) -> StdoutBuffer<std::io::StdoutLock> {
         StdoutBuffer::new(self.stdout.lock())
     }
 
     /// Write bytes to stdout
     pub fn write_stdout(&self, bytes: &[u8]) -> Result<(), UiError> {
         let mut stdout = self.stdout.lock();
 
-        stdout
-            .write_all(bytes)
-            .or_else(|e| handle_stdout_error(e))?;
+        stdout.write_all(bytes).or_else(handle_stdout_error)?;
 
-        stdout.flush().or_else(|e| handle_stdout_error(e))
+        stdout.flush().or_else(handle_stdout_error)
     }
 
     /// Write bytes to stderr
     pub fn write_stderr(&self, bytes: &[u8]) -> Result<(), UiError> {
         let mut stderr = self.stderr.lock();
 
-        stderr
-            .write_all(bytes)
-            .or_else(|e| handle_stderr_error(e))?;
+        stderr.write_all(bytes).or_else(handle_stderr_error)?;
 
-        stderr.flush().or_else(|e| handle_stderr_error(e))
+        stderr.flush().or_else(handle_stderr_error)
     }
 }
 
 /// A buffered stdout writer for faster batch printing operations.
 pub struct StdoutBuffer<W: Write> {
     buf: io::BufWriter<W>,
 }
 
 impl<W: Write> StdoutBuffer<W> {
     pub fn new(writer: W) -> Self {
         let buf = io::BufWriter::new(writer);
         Self { buf }
     }
 
     /// Write bytes to stdout buffer
     pub fn write_all(&mut self, bytes: &[u8]) -> Result<(), UiError> {
-        self.buf
-            .write_all(bytes)
-            .or_else(|e| handle_stdout_error(e))
+        self.buf.write_all(bytes).or_else(handle_stdout_error)
     }
 
     /// Flush bytes to stdout
     pub fn flush(&mut self) -> Result<(), UiError> {
-        self.buf.flush().or_else(|e| handle_stdout_error(e))
+        self.buf.flush().or_else(handle_stdout_error)
     }
 }
 
 /// Sometimes writing to stdout is not possible, try writing to stderr to
 /// signal that failure, otherwise just bail.
 fn handle_stdout_error(error: io::Error) -> Result<(), UiError> {
     if let ErrorKind::BrokenPipe = error.kind() {
         // This makes `| head` work for example
         return Ok(());
     }
     let mut stderr = io::stderr();
 
     stderr
         .write_all(&[b"abort: ", error.to_string().as_bytes(), b"\n"].concat())
-        .map_err(|e| UiError::StderrError(e))?;
+        .map_err(UiError::StderrError)?;
 
-    stderr.flush().map_err(|e| UiError::StderrError(e))?;
+    stderr.flush().map_err(UiError::StderrError)?;
 
     Err(UiError::StdoutError(error))
 }
 
 /// Sometimes writing to stderr is not possible.
 fn handle_stderr_error(error: io::Error) -> Result<(), UiError> {
     // A broken pipe should not result in a error
     // like with `| head` for example
     if let ErrorKind::BrokenPipe = error.kind() {
         return Ok(());
     }
     Err(UiError::StdoutError(error))
 }